Device for securing a boot to a ski

ABSTRACT

A device for securing a boot to a ski includes a support member disposed between the ski and a sole-element of the boot; one end of the support member is pivotally mounted to the ski to provide a displacement of the boot in a plane perpendicular to the plane of the ski, and the other end of the support member is releasable to allow this displacement. First hinge means connect the support to the sole-element and allows the boot to pivot about an axis perpendicular to the boot. Second hinge means connect the first hinge means to the support member and include a pivot axis transversely extending of the ski, the pivot axis of the first and second hinge means being in constant perpendicularity.

United States Patent 11 1 Salomon I 1111 3,813,109 1451 May 28, 1974 1 4] DEVICE FOR SECURING A BOOT TO A SKI [76] Inventor: Georges Pierre Joseph Salomon, 34,

Ave. de Loverchy, Annecy, France [22] Filed: Mar. 15,1972 21] Appl. No.: 234,933

[30] Foreign Application Priority Data Mar. 18, 1971 France 71.09519 [52] US. Cl 280/1135 Y. [51] Int. Cl. A636 9/08 [58] Field of Search280/1l.35 Y, 11.35 E, 11.35 C,

280/1135 K, 11.35 D, 11.35 A, 11.35 R

6/1928 Switzerland 280/1135 D 134,284 10/1929 Switzerland 280/1135 D Primary ExaminerDavid Schonberg A Assistant Examiner-Milton L. Smith [57] ABSTRACT releasable to allow this displacement. First hinge means connect the support to the sole-element and al- References Cited lows the boot to pivot about an axis perpendicular to UNITED STATES PATENTS the boot. Second hinge means connect the first hinge 3,284,092 11/1966 Rumaner 280/1135 K means the Support member and include a Piv0t axis 3,439,424 1 1970 Gertsch et a1 280/1135 K transversely extending 0f the Ski, the Pivot axis of the 3,504,922 4 1970 Wiley 280/1135 T A fi a second hinge m ans ing in c nstant per- FOREIGN PATENTS 0R APPLICATIONS i I 841,238 2/1939 France... 280/1135 Y 15 Claims, 19 Drawing Figures 1 i )4 41,- 7 i 12 ,3-','--- F3 9- 14 19 30 I 1 1 4 1 I l I j 1 32 27 26 F1 1 21 d PATENTEUMAY 28 I974 SHEEI 1 OF 5 1 MES PATENTED m4 38111109 sum 3 0r 5 o 51 so" 52 PATENTED Y 2 I914 3.813109- SHEET b 0F 5 PATENTEDMAY 28 I974 SHEET 5 0F 5 .1 DEVICE FOR SECURING A BOOT To A SKI.

The present invention relates to a device for securing a boot to a ski. More particularly, the invention relates to a device which allows the boot to move in relation to the ski without complete separation. In other words,

it may be said that this type of device performs a func-- tion similar to that of the conventional safety strap. However, the device according to the invention belongs to the family of devices in which a mounting is arranged between the boot and the ski and is articulated, on the'one hand to the'ski, and on the other hand, to a sole-element of the boot, either the sole itself or an element attached to the boot, during skiing, by any appropriate means.

;Moreover, the device is adapted to be locked in a specific position'in order to ensure that the boot remains on the ski, the lock being releasable at least laterally and vertically, inforder to allow the safety binding to operate. 7

Devices for securing a boot to a ski and having articulated mountings are already known. Devices of this kind may be divided into two groups:

devices designed especially to allow walking on skies;

in these the mounting remains hinged to the ski at one point and allows the skier to climb a slope, for example;

released. For instance, one known device pertaining to,

the first of the groups mentioned above comprises a yoke held to the heel of the boot, to which is hinged a pair of rods arranged to pivot about axes integral with the ski. This arrangement allows the heel to be lifted in relation to the ski, thefront of theboot being accommodated in a safety stop, and a tensioning means assisting the heel of the boot to return to the ski. This type 'of device has numerous parts, is complicated inuse, and is heavier than the conventional systems using hookswhich make it possible to adjust the tension which brings the boot back to the ski as required, i.e. for walking or descending. When adjusted for skiing downhill, this known type of device is locked to rear of i the ski, a safety stop. in front allowing the boot to be released in the event of a twisting fall. To this end, the stop is free to pivot laterally and it cannot be locked while the ski is being used for walking. It will be understood, however, that this arrangement of the yoke in the heel area is not desirable when the skis are being used for walking, since the device allows the boot to move forward in relation to the longitudinal axis of the ski. Since, during walking, it is the front of the boot that guides the ski along the path to follow, this is a serious disadvantage.

Also known is a device consisting of a yoke attached to the ski by means of hinged plates which allow the heel to lift in relation to the ski. This device also allows the ski to be used for walking. The yoke is attached to the sole of the boot and is articulated in relation thereto about an axis located in the plane of the sole. The wings of the yoke are carried on a first plate which is itself ar- 7 ticulated onan axis parallel with the plane of the said sole, and this axis carries a plate which is in turn articulated about a third axis at right angles to thefirst two.

This device has the disadvantage that it fails to allow lateral pivoting of theboot-except in one very special case, namely when the articulated plates are aligned in a'verticalv plane. Lateral pivoting cannot however take place when the boot is in the vicinity of the ski, which it usually is. Thus the lack of freedom of the boot in the horizontal plane is a serious disadvantage of this type of device. Moreover, this type of binding must of necessity be used in conjunction with a safety stop, in order to hold the front part of the boot and to allow lateral safety release.

Still within the first group, devices are known which comprise a flexible plate attached by one end to the ski under a safety stop, the plate being adapted to be connected to, the boot temporarily by means of a part fitting'the heel, and by a long strap. This type of device, however, which was specially designed for walking on skis, can have a safety function only if a safety heel piece is used in conjunction with the front stop.

Among the devices in the second group is one making use of a rigid plate temporarily mounted under the boot, the plate being held to the ski by a safety-locking device. When this lock is released, the boot and the plate leave the ski, but the plate remains attached thereto by a safety strap. In this device, the plate is es- .sentially a part of the safety binding, and if it is to be used for walking, it requires a hinge system attaching it to the ski. I I

Another known device makes use of a system of two plates hinged at one end, one of the said plates being integral with the sole of the boot, while the other pivots about a central fixed axis at right angles to the ski.

Finally, a device is known which consists of a plate i to which the boot is temporarily attached, the plate being hinged to the'ski by means of a ball-joint arranged at the front of the boot. A multi-directionalrelease heel-piece locks the back of the plate to the ski. One disadvantage of this device is that, after a safety release, the front of the foot remains connected to the ski, and if the ski should become embedded in the snow, the foot may besubjected to a dangerous amount of torque; moreover, after a safetyrelease, the use of a ball-joint makes the position of the plate indefinite, as a result of which the skier has to carry out inconvenient and delicate manipulations to get his skisback on again.

These known devices do not allow the boot to move in all planes'in relation to the ski, and they may therefore be somewhat dangerous in the event of a fall.

It is an object of the present invention to eliminate the foregoing disadvantages and to provide the boot with a freedom of movement hitherto unknown.

The device according to the invention comprises a mounting arranged between the ski and a sole-element of the boot and connected to the ski by one end in such a manner that the mounting may pivot about this end in a plane at right angles to the ski, the other end of the mounting being releasable in order to make this movement possible; anda means of articulation connecting the mounting to the sole-element of the boot and allowing the boot to pivot about an axis which is always at right angles thereto. The device is characterized in that the connection between the hinge and the mounting is assured by a second hinge pivoting about an axis at right angles to the length of the ski, the axes about which these two hinges pivot being permanently perpendicular. Theaxis of the second hinge preferably lies in a plane passing through the skiers tibia.

The arrangement according to the present invention provides three degrees of freedom for the boot in relation to the ski, to wit:

rocking of the boot from front to rear;

rocking of the boot from rear to front;

pivoting of the boot in the plane of the sole.

In addition to this, the device may with advantage comprise an element consisting of an axis which, in the position of rest, will be substantially parallel with the longitudinal axis of the ski, around which the boot may rock when it is no longer integral with the ski; this therefore constitutes a possible fourth degree of freedom for the boot.

The mounting in question may consist of:

either a plate, a rod, and a series of rigid rods;

or a flexible plate capable of being deformed.

The rigid plates may if necessary be telescopic.

The device according to the invention further comprises means for locking the boot axially to the ski, with lateral safety release, and means for maintaining the boot parallel with the ski, with vertical safety release.

The lateral locking means oppose free rotation of the boot about the axis of the first hinge, while the vertical means oppose, on the one hand, any movement of the mounting and, on the other hand, any rocking of the boot about the axis of the second hinge.

It will be observed that the safety binding consisting of the boot locking and retaining means will, with advantage, be mounted in such a manner that it is movable on, or detachable from, the ski, so that its removal allows the ski-walking" device to operate.

Several examples of embodiment of the present invention will now be described, such examples being in no way restrictive, with reference to the drawings attached hereto, wherein:

FIG. 1 shows a longitudinal section of a first form of execution of the device according to the invention;

FIGS. 2, 3, 4 are diagrams illustrating various ways of obtaining three or four degrees of freedom for the boot;

FIG. I I shows an elevational view ofa third, and preferred, form ofexecution ofthe invention, in which the locking means and the maintaining means are separate;

F [G 12 shows, to anenlarged scale, a horizontal section along the line XII-XII in FIG. 11 of a locking means for the boot;

FIG. 13 is a plan view, in the direction of arrow XIII in FIG. 11, of the boot-maintaining means, the lower half of FIG. 13 being a horizontal section;

FIG. 14 is a section along the line XIV-XIVin FIG. 13;

FIG. 15 shows an elevational view of a fourth form of execution of the invention;

FIGS. 16, l7, 18, 19 are diagrams showing variants indicating the various positions of the locking and maintaining means.

In the following description, the same elements carry the same reference numerals. Moreover, this description will deal with the case in which the boot is temporarily attached to a plate located as shown between the sole of the boot and the ski. It will be understood, however that the sole of the boot itself may be arranged to allow the use of the device according to the invention.

FIG. I shows a ski l and a ski boot 2 with a sole 3. Attached to ski l, for example by means of screws, is a bracket 4 comprising a horizontal axis 5 arranged transversely of the ski, to which is hinged a plate 6 adapted to pivot in the direction of arrow F At the end remote from hinge 5, plate 6 is in the shape of a fork traversed by an axis 7 parallel with axis 5. Axis 7 carries, between the two arms of the fork, a rod8 with a vertical axis 8' adapted to pivot about axis 7 in the direction of arrow F Rod 8 carries a cylindrical head 9 arranged to rotate in a part 10 attached, by means of screws, for example, in a cavity in a plate or platine 11 running substantially parallel with the ski.

Plate 11 is made integral with boot 2 by engaging the front of the boot in a jaw 12 integral with the plate and by locking the rear of the boot by means of a conventional tensioning system 13 which may consist, for example, of a yoke, the arms of which are engaged at one end in holes in a series of holes 14 arranged in plate 11, the yoke being kept locked to the heel of the boot by means ofa lever 15, which may be an eccentric. Since this tensioning system is conventional, it will not be described here in detail.

The series of holes 14 is provided to allow the plate to fit boots of differentsizes.

Axis 8' of rod 8 is preferably in alignment with axis X-X of the skiers tibia (not shown) and plate 11 may turn, in its plane, in the direction of arrow F around cylindrical head 9.

Plate 6 carries in the vicinity of hinge 5 a support 16 on which the front of plate 11 rests. This support may consist of any appropriate anti-friction element.

The safety binding provided for this device is mounted in a housing 17 adapted to slide longitudinally in rails 18 integral with the ski and to be locked either in the forward position shown in this figure (which is the position for skiing) or in a rearward position in which the safety binding is not used and which is therefore the position for walking.

The safety binding comprises a first piston I9 arranged to slide in housing 17, the rounded external end of the said piston co-operating with a vertical ramp 20, of generally V-shape, arranged at the rear end of plate 11. A second piston 21, parallel with the first, has an outside and exhibiting an inclined slope 22 cooperating with wedge-shaped end 23 of plate 11.

The ends of pistons 19 and 21 located in housing 17 are in the form of two opposing receptacles 24,25 containing a rocker 26 urged in a forward direction by a spring 27, the load on which is adjustable by means of a screw 28. The lower part of the rocker has a support point 29 about which it may pivot and two spherical enlargements 30,31 which are kept in contact with pistons l9 and 21 respectively.

It will also be observed that the back of plate 11 rests upon a resilient button 32 mounted on a spring 33 within housing 17. Themethod of operation of the safety binding is as follows: when a lateral stress is applied to the boot, the latter tends to rotate about head hasemerged completely from ramp 20. It will'be noted that the movement of rocker 26about its pivot point 29 increases, by reaction, the pressure of piston 21 on plate 6,.which is thus firmly held.

. On theother hand, in the event of a forward fall, plate 6 begins to pivot vertically about axis 5 against the action of piston 21, which it tends to push back. However, co-operation between the chamfered ends of piston 21 (FIG. 7) and of plate 6 allows resilient travel. Before the ends of the piston and the plate separate, plate 11 has pivoted about axis 5 sufficiently to allow piston 19 toescape from-ramp 20; when this happens, the relative positions of the ends of plate 6 and piston 22 are as shown in FIG. 7 indotted lines. In order that this situation may come about, it is desirable that resilient travel D of plate 6 be greater than the distance a (FIG. 1) between the upper edge of piston 19 and the lower surface of plate 1 1.

Once piston 19 has left ramp 20, the top of rocker 26 'tion of arrow F It is obvious that in the event of a twisting fall, plate 6 will still be released by piston 21.

- In the foregoing,cnsideration has been given to the case in which the boot is attached to, an intermediate plate 11. It will be understood, however, that to attach directly to the sole of the boot part 10, in which cylindrical head 9 of rod 8 is mounted, would not constitute a departure from the scope'of the invention.

The diagram in FIG. 2 breaks down the three degrees of freedom allowed by the device in FIG. I.

An additional degree of freedom could, however, be provided by allowing the boot to rock in the direction of arrow 4 about its longitudinal axis. This might be accomplished, for example, by using, instead of plate 6, a rod hinged about axis 5 and surrounded by a sleeve carrying support 16 and double hinge 7 8'.

Another type of device having four degrees of freedom could also be obtained by replacing rigid plate 6 with a flexible and deformable plate 35 (FIG. 3). One end of the platewould be attached, for example by means of screws, to a support 36, while its other end would be fitted'with the double hinge 7 8'. The deformability of this plate would allow it to pivot in the direction of arrow F and to deform laterally in the direction of arrow F Also conceivable is another type of device such as that shown schematically in FIG. 4, in which cylindrical head 9 of rod 8 is replaced by a ball-joint 37 allowing the boot to move in any direction whatever about rod 8; this would not only provide a fourth degree of freedom in the direction of arrow F,, but also several intermediate degrees of freedom.

' FIG. 5 shows a variant of the device according to the invention in which a ball-joint 35 of this kind is used.

' i In this case the support is in the form of a rod 38 hinged to the ski at 5, the rear end of the rod carrying, as in FIG. 1, a horizontal axis 7 around which a rod 8 rotates, the rod being integral with ball-joint 37. In this case the front of plate 11 is supported on two vertical wings 38' attached to the ski on each side of rod 38.

The safety binding in this variant is identical with that shown in FIG. 1, and it will therefore not be described again. FIG. 6, however, shows end 23 of rod 38 which co-operate with end 22 of the safety-binding piston.

As regards the safety binding, conceivable appropriate arrangements may be divided into two groups:

one in which the means for locking and maintaining the boot are controlled by means of a joint resilient system; the locking and maintaining means are actuated by independent resilient systems.

The safety binding in FIGS. 1 to 5 belong to the first group, as do those in the variants illustrated schematically in FIGS. 8 to 10. Thus in FIGS the safety binding is similar to the one just described, locking means 39 and maintaining means 40 constituting a single assembly loaded by means of a single spring 41 resting against a fixed part 42' integral with ski 1. The safety binding in FIGS. 1, 5, 8 co-operates with the rear parts of soleelement 11 and plate 6.

On the other hand, in FIG. 9, the assembly comprising locking means 39 and maintaining means 40 cooperates with the front of plate 11 and with the front of support 6, which has an extension 41 provided to that end. The safety binding is subjected to the action of a common spring 41 also resting against a fixed part 42 integral with ski 1. Obviously the safety binding in FIG. 9 could be of the same type as that illustrated in FIGS. 1 and 5 Another arrangement of safety binding might be that shown in dotted lines in FIG. 8 between the ends of plate 6. This safety binding 43 might consist of two vertical wings 44 hinged at 45 to theski and urged towards each other by a spring 46. Wings 44 have a first ramp 47 designed to co-operate with one edge of plate 6, and a second ramp 48 co-operating with a profile 49 corresponding to sole-element ll of the boot. Various designs of the second group of safety bindings are shown in FIGS. 16 to 19. Thus FIG. 16 shows a means 60 for maintaining the boot having a spring 51 and co-operating with a front extension 52 of plate 6, while a locking means 53 for the boot (similar to that shown in FIGS. 11 and 12) co-operates with a part 54 integral with sole-element 11 of the boot, and is acted upon by a spring 55 resting against a part integral with plate 6.

In FIG. 17, the boot-locking means may be similar to that in FIG. 16, while maintaining means 50 cooperates with rear end 56 of plate 6.

In FIG. 18, the boot-locking means is identical with that in FIGS. 16 and 17, while maintaining means 57 is mounted on a pedestal 58 and co-operates directly with sole-element 11 of the boot.

As shown in FIG. 19, it would also be possible to provide maintaining means 50 similar to that in FIG. 17, while the locking means would consist of a finger 59 mounted in a cavity 60 in sole-element 11 of the boot The variants illustrated in FIGS. 11 to 15 show such separate locking and maintaining means.

With reference to FIG. 11, support 6, in the form of a rigid plate, is hinged, as in FIGS. 1 and 5, about a horizontal axis 5 and has double hinge 7 8' at its rearend. Head 9 of rod 8 is housed in part 63 (FIG. 12) attached by screws 64 under sole-element or plate 11, part 63 having a generally V -shaped vertical ramp 65 cooperating with a spring finger 66 sliding in a support 67 attached by screws 68 to plate 6. Finger 66 is kept in contact with part 63 by means of a spring 69, the tension of which is adjustable by means of a screw 70.

The boot maintaining means, indicated in a general way by 71, comprises a housing 72 (see FIGS. 13, 14) attached by screws 73 to ski I. Mounted in a longitudinal cavity in this housing is a sleeve 75 traversed by a screw 76 to which is screwed a conical core 77 which moves longitudinally when screw 76 is operated. Screw 76 is of course prevented from moving longitudinally, on the one hand by its head and, on the other hand, by a stop 78 located at its free end. Housing 72 also contains two lateral chambers 79 accommodating pistons 80. The bottoms of chambers 79 are drilled to receive a bush 8] having a conical internal surface cooperating with conical core 77. Located between each piston 80 and corresponding bush 81 is a spring 82. It will be understood that screw 76 makes it possible to adjust the tension of springs 82 by a wedge effect.

Each piston 80 has a groove 83 on its lateral face (FIG. 14), the upper surface 84 of which is at an angle and thus constitutes a nose with a chamfer 85 on the upper surface. Pistons 80 are designed to co-operate with a corresponding profile 86 on the sides of an opening 87 provided in plate 6 at the location of the bootmaintaining means. The lateral edges ofthis opening 87 also have a recess 88 to accommodate noses 84,85 when plate 6 is in the position shown in FIG. I].

With this arrangement, it will be understood that ifa stress occurs tending to cause plate 6 to pivot in the direction of arrow F this plate will lift in the direction of the arrows in FIG. 14, and will push pistons 80 into housing 72 against the action of springs 82.

It will be seen that this safety binding permits stepin fitting of the skis; this is due to chamfers 85 on the pistons which co-operate with inclined surface 86 of plate 6. Furthermore, co-operation between noses 84,85 and plate 6 ensures resilient travel of the device, as explained in connection with FIG. 1.

Finally, FIG. shows a variant in which pivot axis 5 for plate 6 is located in the vicinity of the heel of the boot. Securing systems 67 and 71 are the same as those described in connection with FIG. 11.

It is obvious, however, that with a device ofthis kind, when the binding releases vertically, the boot has a tendency to move backwards as a result of the lever action of plate 6. In order to allow this backward movement to take place, a front support 89 has been provided for the sole-element of the boot, said support comprising rolling means, for instance a ball or a roller, rotating about a horizontal axis and facilitating the movement of the boot.

What I claim is:

l. A device for securing a boot to a ski comprising a support member disposed between said ski and a soleelement of said boot, said support member having one end pivotally mounted to said ski to provide a displacement of said support member in a plane perpendicular to the plane of said ski and'having the other end releasably mounted to allow said displacement; means for locking the boot axially to the ski with lateral safety release; and means for maintaining the boot parallel with the ski with vertical safety release; first hinge means connecting said support member to said sole-element to allow said boot to pivot about an axis perpendicular to said boot; and second hinge means connecting said first hinge means and said support member and including a pivot axis transversely extending of said ski, the pivot axis of said first and second hinge means being in constant perpendicularity, said locking means opposing free rotation of the boot about the axis of the first hinge means and said maintaining means opposing movement of the support member and pivotal movement of the boot about the axis of the second hinge means.

2. A device according to claim 1, further comprising an element having, in a position of rest, an axis parallel with the-longitudinal axis of the ski and around which the boot may pivot when not fixedly mounted on the ski.

3. A device according to claim 2, wherein said element includes said support member ensuring lateral rocking of said boot and vertical displacement thereof around said one end of said support member connected to the ski. I

4. A device according to claim 3, wherein said support member consists of a flexible element attached to .the ski at one end and deformable both longitudinally and transversely.

5. A device according to claim 3, wherein said support member is a rigid element hinged to the ski at one end thereof and pivotable about an axis located transversely of the ski, said support member having at the other end two hingeshaving their axes at right angles to each other, and having means to allow said two hinges to rotate about the longitudinal axis of the support member and in a plane including the two axes of said two hinges.

6. A device according to claim 3, wherein said maintaining means are mounted detachably to the ski whereby the ski may be used for walking by removing said maintaining means.

7. A device according to claim 2, wherein said first hinge consists of a ball-joint allowing said boot to pivot laterally about an axis at right angles to the sole of the boot.

8. A device according to claim 1, wherein the axis of said second hinge means is located in the transverse plane of the ski extending through the axis of the skiers tibia.

9. A device according to claim I, wherein said locking means co-operate with the sole-element of the boot, and said maintaining means co-operate with the support member.

10. A device according to claim I, wherein said locking and maintaining means exhibit profiles cooperating with complementary profiles on the soleelement and the support member, respectively, under the action of a common resilient system.

11. A device according to claim 1, wherein said support member is a rigid plate hinged at one end to the ski and connected at its other end to the sole-element of the boot through a double hinge formed by the first and second hinge means; the end of the plate carrying 9 the double hinge comprising a ramp running transversely of the ski and co-operating with a corresponding ramp on the end of a first horizontal piston mounted in a housing integral with the ski in a manner enabling it to slide longitudinally; and the end of the sole-element located on the same side as the end of the plate, in relation to the double hinge, comprising a V- shaped vertical ramp co-operating with a second horizontal piston mounted in the housing integral with the ski and sliding longitudinally therein, the two pistons being articulated on the ends of a rocker subjected to the action of a central spring and maintaining the pistons in the position in which the plate and the soleelement are locked.

12. A device according to claim 11, wherein said housing has a projection about which the rocker may pivot when one of vertical or lateral locks is open in safety.

13. A device according to claim 1, wherein said locking and maintaining means have profiles co-operating with complementary profiles on the sole-element and the support member, respectively, under the action of 10 separate resilient systems.

14. A device according to claim 1, wherein said support member is a rigid plate hinged at one end thereof to the ski and connected at its other end to the soleelement of the boot by means of a double hinge formed by the first and second hinge means; said plate including, between its two ends, lateral ramps co-operating with maintaining-means with a vertical safety release, consisting of a housing attached to the ski and comprising two opposing spring-loaded pistons extending transversely of the ski, said pistons exhibiting, respectively, profiles co-operating with the ramps on the plate; the sole-element of the boot comprising, in the vicinity of its articulated connection to the plate, a V-shaped vertical ramp co-operating with locking means with a lateral safety release, consisting of a housing attached to the plate and containing a locking piston urged by means of a spring towards the V-shaped ramp.

15. A device according to claim 1, wherein said maintaining means both co-operate with ramps on the sole-element of the boot. 

1. A device for securing a boot to a ski comprising a support member disposed between said ski and a sole-element of said boot, said support member having one end pivotally mounted to said ski to provide a displacement of said support member in a plane perpendicular to the plane of said ski and having the other end releasably mounted to allow said displacement; means for locking the boot axially to the ski with lateral safety release; and means for maintaining the boot parallel with the ski with vertical safety release; first hinge means connecting said support member to said sole-element to allow said boot to pivot about an axis perpendicular to said boot; and second hinge means connecting said first hinge means and said support member and including a pivot axis transversely extending of said ski, the pivot axis of said first and second hinge means being in constant perpendicularity, said locking means opposing free rotation of the boot about the axis of the first hinge means and said maintaining means opposing movement of the support member and pivotal movement of the boot about the axis of the second hinge means.
 2. A device according to claim 1, further comprising an element having, in a position of rest, an axis parallel with the longitudinal axis of the ski and around which the boot may pivot when not fixedly mounted on the ski.
 3. A device according to claim 2, wherein said element includes said support member ensuring lateral rocking of said boot and vertical displacement thereof around said one end of said support member connected to the ski.
 4. A device according to claim 3, wherein said support member consists of a flexible element attached to the ski at one end and deformable both longitudinally and transversely.
 5. A device according to claim 3, wherein said support member is a rigid element hinged to the ski at one end thereof and pivotable about an axis located transversely of the ski, said support member having at the other end two hinges having their axes at right angles to each other, and having means to allow said two hinges to rotate about the longitudinal axis of the support member and in a plane including the two axes of said two hinges.
 6. A device according to claim 3, wherein said maintaining means are mounted detachably to the ski whereby the ski may be used for walking by removing said maintaining means.
 7. A device according to claim 2, wherein said first hinge consists of a ball-joint allowing said boot to pivot laterally about an axis at right angles to the sole of the boot.
 8. A device according to claim 1, wherein the axis of said second hinge means is located in the transverse plane of the ski extending through the axis of the skier''s tibia.
 9. A device according to claim 1, wherein said locking means co-opErate with the sole-element of the boot, and said maintaining means co-operate with the support member.
 10. A device according to claim 1, wherein said locking and maintaining means exhibit profiles co-operating with complementary profiles on the sole-element and the support member, respectively, under the action of a common resilient system.
 11. A device according to claim 1, wherein said support member is a rigid plate hinged at one end to the ski and connected at its other end to the sole-element of the boot through a double hinge formed by the first and second hinge means; the end of the plate carrying the double hinge comprising a ramp running transversely of the ski and co-operating with a corresponding ramp on the end of a first horizontal piston mounted in a housing integral with the ski in a manner enabling it to slide longitudinally; and the end of the sole-element located on the same side as the end of the plate, in relation to the double hinge, comprising a V-shaped vertical ramp co-operating with a second horizontal piston mounted in the housing integral with the ski and sliding longitudinally therein, the two pistons being articulated on the ends of a rocker subjected to the action of a central spring and maintaining the pistons in the position in which the plate and the sole-element are locked.
 12. A device according to claim 11, wherein said housing has a projection about which the rocker may pivot when one of vertical or lateral locks is open in safety.
 13. A device according to claim 1, wherein said locking and maintaining means have profiles co-operating with complementary profiles on the sole-element and the support member, respectively, under the action of separate resilient systems.
 14. A device according to claim 1, wherein said support member is a rigid plate hinged at one end thereof to the ski and connected at its other end to the sole-element of the boot by means of a double hinge formed by the first and second hinge means; said plate including, between its two ends, lateral ramps co-operating with maintaining means with a vertical safety release, consisting of a housing attached to the ski and comprising two opposing spring-loaded pistons extending transversely of the ski, said pistons exhibiting, respectively, profiles co-operating with the ramps on the plate; the sole-element of the boot comprising, in the vicinity of its articulated connection to the plate, a V-shaped vertical ramp co-operating with locking means with a lateral safety release, consisting of a housing attached to the plate and containing a locking piston urged by means of a spring towards the V-shaped ramp.
 15. A device according to claim 1, wherein said maintaining means both co-operate with ramps on the sole-element of the boot. 